Concept explainers
It is well known that cold air feels much colder in windy weather than what the thermometer reading indicates because of the “chilling effect” of the wind. This effect is due to the increase in the convection heat transfer coefficient with increasing air velocities. The equivalent wind chill temperature in °F is given by [ASHRAE, Handbook of Fundamentals (Atlanta, GA, 1993), p. 8.15]
where V is the wind velocity in mi/h and Tambient is the ambient air temperature in °F in calm air, which is taken to be air with light winds at speeds up to 4 mi/h. The constant 91.4°F in the given equation is the mean skin temperature of a resting person in a comfortable environment. Windy air at temperature Tambient and velocity V will feel as cold as the calm air at temperature Tequiv. Using proper conversion factors, obtain an equivalent relation in SI units where V is the wind velocity in km/h and Tambient, is the ambient air temperature in °C.
Want to see the full answer?
Check out a sample textbook solutionChapter 1 Solutions
THERMODYNAMICS-SI ED. EBOOK >I<
Additional Engineering Textbook Solutions
Fox and McDonald's Introduction to Fluid Mechanics
Mechanics of Materials
Applied Fluid Mechanics (7th Edition)
Statics and Mechanics of Materials
Heat and Mass Transfer: Fundamentals and Applications
HEAT+MASS TRANSFER:FUND.+APPL.
- What is the absolute temperature reading in Kelvin(K), if the arbitrary temperature °C reading is thrice to the arbitrary temperature °F reading.arrow_forwardWhat is the value of the maximum temperature in °C?arrow_forwardWhat is the specific internal energy of water at 50°C with a specific enthalpy of 1500 kJ/kg? Report your answer to one decimal place using rounding.arrow_forward
- A new temperature scale called Grande (°Gr) is to be invented where freezing and boiling temperature of water is 34°Gr and 35°Gr respectively. Convert 69°Gr to °Carrow_forwardA certain gasoline gives a hydrometer reading of 66.5 oBaume at 15.6 oC. Using theBureau of Standards Empirical Formula, determine the HHV in kJ/kg.arrow_forwardThe interior contents and materials of a small building weigh 10 tons, and together they have an average specific heat of 0.25 Btu/ (lbm - °F). Neglecting any inefficiency in the furnace, what amount of natural gas must be burned to raise the building's temperature from freezing to 80° F? (Express your answer using three significant figures.) mgan = Ibmarrow_forward
- The average temperature of the atmosphere in the world is approximated as a function of altitude by the relation Tatm = 288.15 − 6.5z where Tatm is the temperature of the atmosphere in K and z is the altitude in km with z = 0 at sea level. Determine the average temperature of the atmosphere outside an airplane that is cruising at an altitude of 12,000 m.arrow_forwardOn a summer day in Narragansett, Rhode Island, the air temperatureis 74 ° F and the barometric pressure is 14.5 lbf/in 2 .Estimate the air density in kg/m 3 .arrow_forwardHow does a pressure measurement of 14.7 psig differ from a pressure measurement of 14.7 psia?arrow_forward
- Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning